KR100480751B1 - Digital video encoding/decoding method and apparatus - Google Patents

Abstract

The present invention relates to a video encoding / decoding method having both a spatial hierarchical structure and an image quality hierarchical structure that efficiently encodes and transmits an object having an arbitrary shape in a continuous motion. The method comprises encoding and encoding video input data consisting of object shape information and texture information inside an object into a spatial hierarchical structure and an image quality hierarchical structure, wherein (a) shape information and texture information are respectively determined. Constructing a spatial hierarchy including one base layer and one or more upper layers by downsampling at a rate; (b) encoding the shape and texture information of the base layer to generate a base bitstream of the base layer; Frequency conversion encoding the difference between the decoded texture information and the original texture information, and constructing a hierarchical structure of image quality for each frequency band; and (c) shape information upsampled in the base layer for each of one or more upper layers. Encoding a difference between the shape information of the layer and the upper layer to generate a basic bitstream of the upper layer, and (b) Encoding a difference between the texture information of the decoded texture information with the upper layer, and the frequency conversion, it characterized in that it comprises the step of configuring the hierarchy, the image quality for each frequency band. According to the present invention, since encoding / decoding can be applied to an object having an arbitrary shape, a separate image quality service is possible for arbitrary objects displayed on the screen.

Description

Video encoding / decoding method and apparatus {Digital video encoding / decoding method and apparatus}

The present invention relates to data encoding and decoding, and in particular, a video encoding / decoding method having both a spatial hierarchical structure and an image quality hierarchical structure that efficiently encodes and transmits an object having an arbitrary shape in a continuous motion. Relates to a device.

Many coding / decoding methods that have been studied so far are related to a method of encoding / decoding a square-shaped image having a constant size, such as a TV screen. Examples are MPEG1, MPEG2, H.261, H.263 and the like.

Most of the existing coding schemes provide only a very limited hierarchical service, and actively cope with a structure in which transmission channel conditions change frequently such as the Internet / Intranet and a wireless network. It was not possible. Spatial scalable with two spatial hierarchies for rectangular screen video in MPEG-2 (ISO / IEC JTC1 / SC29 / WG11 13818-2: MPEG-2 video) coding and SNR scalable coding with two to three layers is proposed, but there are limitations in creating a real application area due to the limitation of the number of layers. In addition, MPEG-4 (ISO / IEC JTC1 / SC29 / WG11 14496-2: MPEG-4 video), which proposes an efficient compression method for arbitrarily shaped objects, also provides spatial temporal hierarchies. Although a coding scheme has been proposed, a method that can provide a hierarchical structure of image quality in the same space on a bitstream has not been proposed, and thus has a limitation in improving service quality.

An object of the present invention is to provide a coding scheme having a hierarchical structure of spatial / image quality to enable various quality of service (QoS).

In addition, the present invention provides a scalable coding scheme that allows data to be differentially transmitted according to the limitation of a transmission line or the reception capability of a receiving end in the encoding process. Another technical problem is to provide a hierarchical coding method for an object.

In addition, the present invention provides not only the spatial hierarchical coding but also the quality hierarchical coding (SNR or Fine Granular scalable coding) function that can variably determine the image quality for a predetermined space, and provides a more detailed service quality. It is a technical object of the present invention to provide a method capable of providing a method and to provide a method of decoding the encoded data.

In order to solve the above technical problem, the video encoding method according to the present invention is a method for encoding a video input data consisting of the shape information of the object and the texture information inside the object in a spatial hierarchy and a quality hierarchy (A) downsampling the shape information and the texture information at a predetermined ratio to form a spatial hierarchy including one base layer and one or more upper layers, (b) the shape of the base layer Generating a basic bitstream of the base layer by encoding the information and the texture information, frequency transform encoding the difference between the decoded texture information and the original texture information, and constructing a hierarchical image quality structure for each frequency band; and (c) For each of the one or more upper layers, shape information upstream from the base layer is higher than the shape information. By encoding the difference of the shape information of the layer to generate a basic bitstream of the upper layer, and the frequency conversion encoding of the difference between the texture information and the texture information of the upper layer decoded in the step (b), the image quality layer for each frequency band And constructing the structure.

In order to solve the above technical problem, the video encoding method according to the present invention is a method for encoding a video input data consisting of the shape information of the object and the texture information inside the object in a spatial hierarchy and a quality hierarchy (A) a spatial layer including one base layer downsampled at a largest ratio and one or more upper layers downsampled at a smaller ratio than the base layer by downsampling the shape information and the texture information, respectively; Constructing a structure, (b) shape-coding the shape information of the base layer with respect to the shape information and the texture information of the base layer, (b2) padding the texture information of the base layer, and converting the frequency Encoding and quantizing. (b3) generating the basic bitstream of the base layer by variable length encoding by collecting the data generated in the steps (b1) and (b2), (b4) dequantizing the data generated in the step (b2), Obtaining a difference between the texture information reproduced by inverse frequency conversion and the texture information of the base layer, (b5) encoding the frequency transform with respect to the difference of the step (b4), and classifying each frequency into bits according to respective frequency bands. Generating a stream, (c) with respect to the shape information and texture information of each upper layer, (c1) the difference between the shape information upsampled from the shape information of the base layer to the upper layer and the shape information of the upper layer Shape coding and variable length coding to generate an upper layer basic bitstream; (c2) upsampling the texture information reproduced in the step (b4) to the upper layer; Obtaining a difference between the texture information and the texture information of the upper layer; and (c3) generating a bitstream according to each frequency band by performing frequency conversion encoding on the difference of the step (c2) and classifying by frequency. Characterized by including.

Preferably, the shape information encoding of the step (b1) and the step (b2) of the present invention is hierarchical shape information encoding using a bilinear processing method.

Preferably, the frequency transform encoding of the present invention is a discrete cosine transform.

The frequency transform encoding of the present invention is preferably a discrete wavelet transform.

Steps (b5) and (c3) of the present invention divide a main block having an N 밝기 N pixel size and divide each main block into four sub-blocks for a difference brightness signal, respectively. And dividing the discrete cosine-converted brightness signal for each subblock by a predetermined number of bands, and dividing the color difference signal corresponding to each main block of the brightness signal into blocks of size N / 2 ㅧ N / 2, respectively. And dividing the discrete cosine-converted color difference signal into each block unit by a predetermined number of bands, and reconstructing the discrete cosine transformed brightness signal and the discrete cosine transformed color difference signal for each band to form a hierarchical image quality layer. N is a predetermined integer larger than 2).

Band-by-band recombination of the present invention is preferably made in the main block unit of the brightness signal.

It is preferable that the band-specific recombination of the present invention is made in the whole image unit.

Each layer of the image quality recombined for each band of the present invention is preferably re-coded by a predetermined method.

In the present invention, it is preferable that the discrete cosine transform is performed only on subblocks or blocks having shape information, and the discrete cosine transform is not performed on subblocks or blocks without shape information.

In order to solve the above technical problem, the video encoding apparatus according to the present invention is configured to encode a video input data consisting of the shape information of the object and the texture information inside the object in a spatial hierarchical structure and a quality hierarchical structure. And downsampling the shape information and the texture information, respectively, to form a spatial hierarchy including one base layer downsampled at the largest ratio and one or more upper layers downsampled at a smaller ratio than the base layer. A down-sampling unit to shape-shape the shape information of the base layer; A texture encoding unit that pads, texture transforms and quantizes texture information of the base layer; A first variable length encoder configured to variably encode the data output from the shape encoder 1 and the texture encoder to generate a basic bitstream of the base layer; A texture decoder which inversely quantizes the data output from the texture encoder and reproduces texture information by inverse frequency conversion; A first primary image generating unit generating a difference between texture information reproduced by the texture decoding unit and texture information of the base layer; And a basic layer encoding unit including a first image layer structure generation unit for generating a bitstream according to each frequency band by frequency-converting the difference generated by the first image generating unit and classifying each frequency. An upsampling unit for upsampling the shape information of the base layer to the upper layer and upsampling the texture information reproduced by the texture decoding unit to the upper layer; Two shape encoding units configured to shape-encode the difference between the upsampled shape information and the shape information of the upper layer; A second variable length encoder for variable length encoding the output data of the shape encoder 2 to generate an upper layer basic bitstream; A second image generating unit obtaining a difference between texture information padding output data of the upsampling unit and texture information of the upper layer; At least one higher layer encoding unit including a second image layer structure generation unit for generating a bitstream according to each frequency band by frequency-converting the difference generated by the second image generator and classifying each frequency. It is characterized by including.

Preferably, the shape coding unit 1 and the shape coding unit 2 of the present invention are hierarchical shape information coding units using a bilinear processing method.

Preferably, the texture encoding unit, the first image layer structure generation unit, and the second image layer structure generation unit each include a discrete cosine converter.

Preferably, the texture encoding unit, the first image layer structure generation unit, and the second image layer structure generation unit each include a discrete wavelet converter.

The first image layer structure generating portion and the second image layer structure generating portion of the present invention are divided into main blocks of N ㅧ N size units for the brightness signal of the difference, and each of the main blocks is divided into four subblocks ( sub-block), the discrete cosine-converted brightness signal in each sub-block unit is divided into a predetermined number of bands, and each color difference signal corresponding to each main block of the brightness signal is N / 2 ㅧ N /. It is divided into two-sized blocks, the discrete cosine transformed color difference signal is divided into predetermined number of bands in each block unit, and the discrete cosine transformed brightness signal and the discrete cosine transformed color difference signal are recombined for each band. In this case, N is a predetermined integer greater than two.

The first image layer structure generating unit and the second image layer structure generating unit of the present invention respectively perform discrete cosine transformation for subblocks or blocks having shape information, and discrete cosine for subblocks or blocks without shape information. It is preferable not to convert.

In order to solve the above technical problem, the video decoding method according to the present invention is a method of decoding a coded bitstream composed of a spatial hierarchy and a quality hierarchy, (a) varying the bitstream Classifying the base layer bitstream and one or more upper layer bitstreams with long decoding, (b) generating shape information of the base layer by shape decoding the encoded shape information included in the base layer bitstream; (c) inverse quantizing the encoded texture information included in the base layer bitstream and inverse frequency transform to generate texture information of the base layer, (d) in the image quality hierarchical structure included in the base layer bitstream Sequentially inversely converting the selected bitstreams and adding them to the texture information of the base layer; and (e) For each upper layer up to a selected upper layer among the one or more upper layers, (e1) shape-decoding the shape information of the upper layer included in the upper layer bitstream and adding the shape information to the shape information of the upsampled lower layer; and (e2) sequentially repeating the inverse frequency conversion of the selected bitstreams in the image quality hierarchical structure included in the higher layer bitstream and adding them to the texture information of the upsampled lower layer. .

In order to solve the above technical problem, the video decoding apparatus according to the present invention is a device for decoding a coded bit stream composed of a spatial hierarchical structure and a quality hierarchical structure, while variable length decoding the bit stream, A variable length decoding unit for classifying the base layer bitstream into one or more upper layer bitstreams, and a shape decoding unit 1 for generating shape information of the base layer by shape decoding the encoded shape information included in the base layer bitstream; A texture decoder which inversely quantizes encoded texture information included in the base layer bitstream and inverse frequency transforms to generate texture information of the base layer; And a first layer hierarchical layer decoding unit and a spatial layer having a first image layer hierarchical structure decoding unit to sequentially inverse frequency-convert the bitstreams selected from the image quality hierarchical structure included in the base layer bitstream and add the texture information of the base layer. An upsampling unit for upsampling the shape information of the lower layer immediately before the upper layer and the texture information of the immediately lower layer of the upper layer in the structure to the upper layer; A shape decoding unit 2 for shape decoding the shape information of the upper layer included in the upper layer bitstream and adding the shape information to the shape information of the upsampled lower layer; And at least one upper layer decoding unit including a second image layer structure decoding unit configured to sequentially inverse-frequency convert the bitstreams selected from the image quality hierarchy included in the upper layer bitstream and add the texture information of the upsampled lower layer. It is characterized by including.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, terms to be described below are terms defined in consideration of functions in the present invention, and may be changed according to a user's or operator's intention or custom. Therefore, the definition should be made based on the contents throughout the specification.

As shown in FIG. 2, the mask 2 104 and the padding 1 105 are formed by using the data 102 reduced in size from the input video 102 and the shape information mask 1 101. After the image is generated, the base layer, that is, the bit stream r (BL,; 131) is generated by using the shape encoder 1 (106) and the DCT (Discrete Cosine Transform) 107, which is a frequency transform encoder, and then dequantized it. 110) and the difference 112 between the reproduced image and the original image is obtained through IDCT (Inverse Discrete Cosine Transform; 111).

Next, DCT 113 is performed on this difference, and the coefficient divider 114 classifies each frequency to form a bit stream according to each frequency band. In this way, BSL0 115, BSL1 116, ..., BSL (n) 118 are generated to add the low frequency component BSL0 115 to the base layer 131 according to the addition of the bitstream. The BSNR (0) (132) with improved image quality is created.BSL (n) (118), which is the highest frequency component, is added to enable the bitstream configuration of BSNR (n) with the highest image quality. Makes it possible. Based on the low resolution reproduced image, the mask 3 120 and the padding 2 image 122 are enlarged twice to be applied even when the resolution is increased by applying the same principle to the spatially enlarged image. The difference 123 between the original image 102 and the padding 2 image 122 having the same resolution is obtained, and then DCT 124 is performed on the difference, so that the coefficient divider 125 for each frequency It classifies and constructs a bitstream according to each frequency band. By generating ESL0 (127), ESL1 (128), ..., ESL (n) 130 in this way, ESNR0 (137) and ESNR1 in accordance with the addition of the bitstream from the EL 136, which is the base of the upper layer. (138), ..., ESNR (n) (140) is implemented such that it is possible to variably adjust in the direction of the image quality is improved even at high resolution.

The bitstreams generated according to the encoder configured as described above are decoded according to the apparatus configured in the decoder as shown in FIG. 3 to provide a reproduced image of a spatial / image hierarchy. As shown in FIG. 3, the input bitstream 201 is interpreted by the variable length decoder VLD1 202 and classified into a base layer bitstream 203 and an upper layer bitstream 210. Then, the base layer bitstream 203 again generates a mask 4 205 through the shape decoding unit 1 204 for the bitstream related to the shape information, which becomes the shape information 208 of the base layer and the image information. For the bitstream associated with, the texture information 209 of the base layer is generated through the inverse quantization 206 and the inverse frequency transform encoding apparatus (IDCT) 207. On the other hand, if there is an upper layer, the upper layer is formed by adding the image (213, 218) which doubled the shape information and texture information of the base layer created in the previous process and the information made through the decoder in the same process as the base layer in the upper layer. Shape information 215 and texture information 220 are produced.

On the other hand, the operation principle of the present invention will be described as follows.

2 shows the overall structure of a hierarchical encoder in spatial / image quality according to the present invention. As shown in FIG. 2, the input data includes a mask 1 101 providing shape information of an object and a video 102 providing internal texture information of an object. However, mask information (masks 1, 2, 3) is not required when the entire screen of the rectangle is encoded without any shape. The input image is converted into images of size 1/2 of the width in the down sampling apparatus 103, and then the mask 1 101 becomes the mask 2 104, and the shape encoder 1 106 is used. ) Is compressed into information necessary for transmission. In this case, the shape coder 1 106 uses the scalable shape coding scheme currently employed in version 2 Working Draft of MPEG-4.

The video 102 information is padded to match the shape to form a padding 1 (105) image, wherein padding uses a technique of MPEG-4 video (14496-2). The padding 1 (105) image is basic in the first variable length coding unit (VLC1) 109 together with the shape coding information that is precoded through the DCT 107 and the quantizer 108, which is a type of frequency conversion encoding apparatus. A basic bitstream BL 131 of the layer is generated. This is the bitstream that produces the most basic picture at the lowest resolution. The frequency coefficients quantized through the quantizer 108 obtain a difference 112 between the inverse quantizer 110 and the original image reduced through the IDCT 111, which is an inverse frequency transform encoding apparatus. Next, DCT 113, which is a frequency transform encoding apparatus, is applied to the difference signal, and the DCT coefficients are classified by the coefficient divider 114 according to a predetermined frequency band, thereby BSL (0) 115 and BSL (1). (116), ..., BSL (n) (118).

In this case, an example of constituting each band is divided into a plurality of N × N subblocks 251 of an arbitrary region constituting an image, as shown in FIG. 4 (a), and then a frequency for each subblock. The output data of the transform encoder is classified for each band. An example of classification for an arbitrary subblock k is as follows. N × N luminance component 251 and N / 2 × N / 2 chrominance component data 256 and 257 are classified. The brightness component data is composed of four sub-blocks 252, 253, 254, and 255, and respective bands are combined to form one sub-band data. The chrominance components are added one by one to each group of frequency bands (MELk) for the unit block. To form.

4 (a) shows a block configuration of the brightness component and the color difference component. FIG. 4 (b) shows the band-by-band classification of the coefficients passed through the frequency conversion encoder for each unit block, where ELk 0 (260), ELk 1 (261), ..., ELk 7 (267), etc. are all 8 It can be seen that different bands can be generated. 4 (c) shows a process of forming unit band groups by grouping coefficients existing in four subblocks constituting a brightness component for the same band, and arranged with unique positions according to the subblocks. That is, MELk 0 (270), the set of AC coefficients of the most important low frequency component, MELk 1 (271), ..., the set of AC coefficients existing in the last band. Classified as MELk 7 (277). 5 and 6 show the configuration of frequency coefficient values according to respective bands.

In FIG. 5, the layer is composed of MELk0 305, MELk1 306,... By the arrangement of the frequency components in each block belonging to the eight hierarchical structures for the brightness component data including four subblocks 301, 302, 303, and 304. .., MELk7 312 is shown. 6 shows the coefficient configuration of the frequency components of two color difference signals (Cr 401 and Cb 403). As with the brightness components, the frequency coefficients for each layer are made up to MELk 0, MELk 1, ..., MELk 7.

In this way, it is possible to create a hierarchical structure for an arbitrary unit block k, and then create a hierarchical structure for the entire screen by grouping data in the same band for all subblocks into a BSL (0) 115 and a BSL (1). ) 116, ..., BSL (n) 118. At this time, in order to process the arbitrary shape, it is necessary to inform whether the subblock is inside, boundary, or outside of the shape. That is, as shown in FIG. 7, by displaying the states of the four subblocks for the brightness information as 4-bit data, it is easy to know which blocks belong to the shape information in a predetermined order. As shown in Fig. 7 (a), if all are outside of the shape, it is indicated as “0000” (502). If it is internal, it is indicated by “1111” (532), so that it is possible to know which block belongs to the data placed in each layer. Of course, in the case of the color difference component, if at least one shape information exists in the brightness component, it is determined that the color difference component also exists. As described above, the bitstream having the hierarchical structure of n image quality is reproduced in the spatial base layer, and the data of the base layer is doubled in the upsampling unit 119 to shape-encode the mask 3 120, which is the enlarged shape information. Coded in part 2 (121) to form an upper layer and creating a padding 2 (122) image in the area identified with reference to mask 3 (120), and subtracting this image from the original video (102) With respect to the difference value, the ESL (0) (127), ESL (1) 128, ..., and ESL (n) 130 are generated through the same process as the base layer to have a spatial / image hierarchical structure. The bitstream can be produced.

Meanwhile, a process of decoding the thus-created bitstreams is shown in FIG. 3. As shown in FIG. 3, the input bitstreams are classified into a base layer bitstream 203 and a higher layer bitstream 210 in the variable length decoder VLD1 202. First, the base layer bitstream 203 is further divided into shape information and texture information. The shape information is decoded by the shape decoding unit 1 (204) to generate the mask 4 (205), which becomes the base layer shape information (208). The texture information generates base layer texture information 209 through inverse quantization 206 and IDCT 207 which is an inverse frequency converter. This ends decoding of the base layer.

If the upper layer bitstream 210 exists, the upper layer bitstream 210 is similarly divided into shape information and texture information. The shape information is decoded by the shape decoding unit 2 (211) to generate a mask 5 (212), which is a shape information reproduced in the base layer, and the upsampling unit 213 doubles the information and the adder 214 Are combined to form upper layer shape information 215. The texture information is added to the image generated through the inverse quantization 216 and the inverse frequency converter IDCT 217 by doubling the texture information reproduced in the base layer by the upsampling unit 218 and adding the same in the adder 219 to the upper layer. The texture information 220 is produced. This ends the decoding process for the upper layer. After all processes are completed, the receiving end can reproduce an image having a plurality of hierarchical structures in spatial and image quality.

What has been described above is just one embodiment for implementing a video encoding / decoding method and apparatus according to the present invention, and the present invention is not limited to the above-described embodiment, but is claimed in the following claims. Various changes can be made by those skilled in the art without departing from the gist of the present invention.

       As described above, according to the video encoding / decoding method and apparatus according to the present invention, it is possible to provide various image quality information of various sizes to an object having an arbitrary shape through one bitstream. That is, by reproducing the information having the basic picture quality of the base layer with a minimum of information, and configuring the various bit streams, the picture quality reproduced according to the performance of the transmission line or the receiving end can be variously changed. In addition, since the same type of operation can be repeated for the upper layer enlarged in space, information of various image quality can be provided according to the change of resolution.

In addition, according to the method and apparatus for encoding / decoding a video according to the present invention, encoding / decoding may be applied to an object having an arbitrary shape, so that a separate image quality service may be provided for arbitrary objects displayed on a screen. That is, various quality of service (QoS) services that determine the degree of image quality as the user or provider intends for the required object become possible.

Fig. 1 shows a hierarchical relationship in space and image quality of an image.

2 shows the overall structure of a spatial / resolution scalable encoder according to the present invention.

3 shows the overall structure of a spatial / resolution scalable decoder according to the present invention.

4 illustrates a process of implementing a hierarchical structure of image quality by dividing a frequency band.

5 shows a set of frequency components constituting each layer of brightness information.

6 shows a set of frequency components constituting each layer of chrominance information.

7 is a structural example of a code expressing an information type according to the presence or absence of shape information.

Claims (18)

In the method of encoding the video input data consisting of the shape information of the object and the texture information inside the object in a hierarchical structure of the spatial and image quality (a) downsampling the shape information and the texture information at a predetermined ratio to form a spatial hierarchy including one base layer and one or more upper layers; (b) encoding the shape information and texture information of the base layer to generate a base bitstream of the base layer, frequency-converting the difference between the decoded texture information and the original texture information, and hierarchically structured image quality for each frequency band. Configuring a; And (c) for each of the one or more upper layers, encoding a difference between the shape information upsampled in the base layer and the shape information of the upper layer to generate a basic bitstream of the upper layer, and decoding in step (b) Encoding the difference between the texture information and the texture information of the upper layer, and encoding the video with both the spatial and video quality hierarchies, characterized in that it comprises the steps of: Way. In the method of encoding the video input data consisting of the shape information of the object and the texture information inside the object in a hierarchical structure of the spatial and image quality (a) downsampling the shape information and the texture information, respectively, to form a spatial hierarchy including one base layer downsampled at the largest rate and one or more upper layers downsampled at a rate smaller than the base layer; Constructing; (b) Regarding the shape information and texture information of the base layer, (b1) shape-coding the shape information of the base layer; (b2) padding, frequency converting, and quantizing the texture information of the base layer; (b3) generating a basic bitstream of the base layer by variable length encoding by collecting the data generated in the steps (b1) and (b2); (b4) inversely quantizing the data generated in the step (b2) and obtaining a difference between the texture information reproduced by inverse frequency conversion and the texture information of the base layer; (b5) generating a bitstream according to each frequency band by performing frequency conversion encoding on the difference of step (b4) and classifying each frequency; (c) shape and texture information of each upper layer, (c1) shape encoding the difference between the shape information of the base layer by upsampling the shape information of the base layer and the shape information of the upper layer, and variable length encoding to generate an upper layer basic bitstream; (c2) upsampling the texture information reproduced in the step (b4) to the upper layer and obtaining a difference between the padded texture information and the texture information of the upper layer; And and (c3) generating a bitstream according to each frequency band by performing frequency conversion encoding on the difference of step (c2) and classifying each frequency. Video encoding method having a. The method of claim 2, And (b1) and (b2), wherein the shape information encoding comprises hierarchical shape information encoding using a bilinear processing method. The method of claim 2, And the frequency transform encoding comprises a discrete cosine transform. The method of claim 2, And the frequency transform encoding is a discrete wavelet transform. The method of claim 4, wherein step (b5) and step (c3) are respectively The difference brightness signal is divided into main blocks of N ㅧ N pixel size, each main block is divided into four sub-blocks, and the discrete cosine-converted brightness signal of each sub block is predetermined. Divide by number of bands, For the color difference signal corresponding to each main block of the brightness signal, the color difference signal is divided into N / 2 ㅧ N / 2 size blocks, and the discrete cosine transformed color difference signal in each block unit is divided into a predetermined number of bands. A video encoding method having a spatial hierarchical structure and an image quality hierarchical structure, wherein the discrete cosine transformed brightness signal and the discrete cosine transformed color difference signal are recombined for each band to form a hierarchical image quality. Greater than a given integer). The method of claim 6, Recombination for each band is a video encoding method having a spatial hierarchical structure and a quality hierarchical structure characterized in that the unit of the main block of the brightness signal. The method of claim 6, A video encoding method having a spatial hierarchical structure and a quality hierarchical structure, characterized in that recombination for each band is performed on an entire image unit. The method of claim 6, And each layer of the image quality recombined for each band is recoded by a predetermined method. The method of claim 6, Discrete cosine transform for only subblocks or blocks with shape information, and discrete cosine transform for subblocks or blocks without shape information, video coding with both spatial and image quality hierarchies Way. In the device for encoding the video input data consisting of the shape information of the object and the texture information inside the object in a spatial hierarchy and image quality hierarchical structure, Downsampling the shape information and the texture information, respectively, to form a spatial hierarchy including one base layer downsampled at the largest rate and one or more upper layers downsampled at a smaller rate than the base layer. Sampling unit; A shape encoding unit 1 for shape coding the shape information of the base layer; A texture encoding unit that pads, texture transforms and quantizes texture information of the base layer; A first variable length encoder configured to variably encode the data output from the shape encoder 1 and the texture encoder to generate a basic bitstream of the base layer; A texture decoder which inversely quantizes the data output from the texture encoder and reproduces texture information by inverse frequency conversion; A first primary image generating unit generating a difference between texture information reproduced by the texture decoding unit and texture information of the base layer; And a basic layer encoding unit including a first image layer structure generation unit for generating a bitstream according to each frequency band by frequency-converting the difference generated by the first image generating unit and classifying each frequency. And An upsampling unit for upsampling the shape information of the base layer to the upper layer and upsampling the texture information reproduced by the texture decoding unit to the upper layer; A shape encoding unit 2 for shape encoding a difference between the upsampled shape information and the shape information of the upper layer; A second variable length encoder for variable length encoding the output data of the shape encoder 2 to generate an upper layer basic bitstream; A second image generating unit obtaining a difference between texture information padding output data of the upsampling unit and texture information of the upper layer; At least one higher layer encoding unit including a second image layer structure generation unit for generating a bitstream according to each frequency band by frequency-converting the difference generated by the second image generator and classifying each frequency. And a video encoding apparatus having a spatial hierarchy and a quality hierarchy. The method of claim 11, And the shape encoding unit 1 and the shape encoding unit 2 are hierarchical shape information encoding units using a bilinear processing method. 12. The spatial hierarchical structure and the hierarchical image quality structure according to claim 11, wherein the texture encoding unit, the first image hierarchy structure generation unit, and the second image hierarchy structure generation unit each include a discrete cosine transformer. Video encoding apparatus having at the same time. The method of claim 11, The video encoding apparatus having both a spatial hierarchical structure and a quality hierarchical structure, wherein the texture encoder, the first image layer structure generator, and the second image layer structure generator each include a discrete wavelet converter. . The method of claim 13, Each of the first image layer structure generation unit and the second image layer structure generation unit divides the brightness signal of the difference into main blocks of N ㅧ N size units, and divides each main block into four subblocks (sub-). block), and the discrete cosine-converted brightness signal in each subblock unit for each predetermined number of bands, For the color difference signal corresponding to each main block of the brightness signal, the color difference signal is divided into N / 2 ㅧ N / 2 size blocks, and the discrete cosine transformed color difference signal in each block unit is divided into a predetermined number of bands. A video encoding apparatus having a spatial hierarchical structure and an image quality hierarchical structure comprising recombining a discrete cosine transformed brightness signal and a discrete cosine transformed color difference signal for each band to form a hierarchical image quality (where N is 2). Greater than a given integer). 16. The subblock or block according to claim 15, wherein each of the first image layer structure generation unit and the second image layer structure generation unit performs discrete cosine transformation only on subblocks or blocks having shape information, and has no shape information. The video encoding apparatus having the spatial hierarchical structure and the hierarchical image quality structure at the same time, characterized in that no discrete cosine transform is performed on the. In the method for decoding a coded bit stream consisting of a spatial hierarchical structure and a quality hierarchical structure, (a) classifying the bitstream into a base layer bitstream and one or more upper layer bitstreams, while variable length decoding the bitstream; (b) shape-decoding the encoded shape information included in the base layer bitstream to generate shape information of the base layer; (c) inverse quantizing the encoded texture information included in the base layer bitstream and inverse frequency transforming to generate texture information of the base layer; (d) sequentially inverse frequency converting the bitstreams selected from the image quality hierarchical structure included in the base layer bitstream and adding them to texture information of the base layer; And (e) for each upper layer up to a selected upper layer among the one or more upper layers, (e1) shape decoding the shape information of the upper layer included in the upper layer bitstream and adding the shape information to the shape information of the upsampled lower layer; And (e2) sequentially repeating the inverse frequency conversion of the selected bitstreams in the image quality hierarchy included in the higher layer bitstream and adding them to the texture information of the upsampled lower layer. A video decoding method having a spatial hierarchy and a quality hierarchy. An apparatus for decoding a coded bitstream consisting of a spatial hierarchical structure and an image quality hierarchical structure, A variable length decoding unit classifying the bit stream into a base layer bitstream and one or more upper layer bitstreams while variable length decoding the bitstream; A shape decoding unit 1 generating shape information of the base layer by shape decoding the encoded shape information included in the base layer bitstream; A texture decoder which inversely quantizes encoded texture information included in the base layer bitstream and inverse frequency transforms to generate texture information of the base layer; And a basic layer decoding unit including a first image layer structure decoding unit which sequentially converts bitstreams selected in the image quality hierarchical structure included in the base layer bitstream and adds the texture information of the base layer to the texture information of the base layer. And An upsampling unit for upsampling the shape information of the lower layer immediately before the upper layer and the texture information of the immediately lower layer of the upper layer in the spatial hierarchical structure to the upper layer; A shape decoding unit 2 for shape decoding the shape information of the upper layer included in the upper layer bitstream and adding the shape information to the shape information of the upsampled lower layer; And at least one upper layer decoding unit including a second image layer structure decoding unit configured to sequentially inverse-frequency convert the bitstreams selected from the image quality hierarchy included in the upper layer bitstream and add the texture information of the upsampled lower layer. A video decoding apparatus having both a spatial hierarchy and a quality hierarchy.